Question

At time t = 0, two bodies A and B are at the
same point. A moves with constant velocity
V and B starts from rest and moves with
constant acceleration. Relative velocity of B
with respect to A when the bodies meet each
other is
1)V/2
2)V/3
3) V
4) 2V​

Answer 1

Explanation:

Let the final relative velocity of B wrt A, when it crosses A, be: v

′

.

It is given initial relative velocity of B wrt A is: 0−V=−V

Initial relative displacement and final relative displacement is 0 as the particles are at the same position initially and finally. Hence, total relative displacement of B wrt A is 0.

From third equation of motion,

v

f

2

=v

i

2

+2as

v

′2

=V

2

v

′

=±V

As seen before, −V corresponds to the initial relative velocity.

Hence, +V corresponds to final relative velocity.